Thanks for the info on the camera. However, maybe I missed it, but how did you get the camera wire from inside to outside the car. Did you just put it through the hatch door and let the door close on it or did you have a drill hole with a separate path?

Sorry for late response.
Where the light for the number plate is.
Take away the plastic inside behind the number plate, then you see it.

Looks to me the main harness is there but there is no camera harness wire it to the trunk. I open my hatch and didn't see any OEM camera plug. I went to junk yard and got the OEM camera but now I have to find the harness to plug into.

Thank you for the schema @FreeYourSoul!
Hope this will help someone or help me to remember if in the future I need to do the same thing.

What you'll need:
1. Any Head Unit or monitor which support REAR CAMERA INPUT ( Mine's JOYING JY-UL135N2)
2. Pry Tools
3. Rear Camera (of course!) and its bolts, I use this as the rear cam
4. A lot of cable ties, electrical tapes and patience
5. Some Head Unit will require you to connect their BACK/REAR VIEW POWER connector. Read or Google what you need to do with your Head Unit's brand
6. Just open the LEFT panel! I made a mistake before by opening the right panel first